Skiving-machine.



E. P. NICHOLS.

SKIVING MACHINE.

APPLICATION FILED MAY 4. 1915.

1,295,104. Patented Nov. 14, 1916.

2 SHEETS-SHEET l- 6 I Nu m mm lo .9

E. P. NICHOLS.

SKIVING MACHINE.

APPLICATION FILED MAY 4. 1915.

1 ,205, 1 04., Patented Nov. 14, 1916.

2 SHEETS-SHEET 2.

V Be it known that I, ELME-R ELMER r'. NICHOLS, E MANCHESTER, NEW HAMPSHIRE, AssIG oR To LA'cENE MANU- EACTURING COMPANY, OF MANCHESTER, NEW HAMPSHI E, A CORPORATION OF MAINE.

T 0 all whom it may concern:

v P. NICHOLS, a citizen of'the United States, and resident of Manchester, in the State of New Hampshire, have invented an Improvement in skiving-Machines, of which the following description, in connection with the accompanying drawings, is a specification, like letters-on the drawings representing like parts.

y shaving, splitting or skiving leather, the ob-: ject of my present invention being to render practicable and advantageous the skiving of the leather by means of a knife having a single bevel'without the danger of gouging or improperly skiving the leather piece, my present application being a continuation of my application Ser. No. 875,377, filed December 3, 1914, where I have shown and describedone embodiment or specific application of my invention which is generically set forth and claimed in the present applica- "tion in connection with another species.

Said twospecies are, however, respectively claimed specifically in their respect1ve ap-' plications.

It has long been considered desirable in leather splitting or skiving machines to employ a knife beveled on one side only, but this has been impossible because such a knife in the cutting machines heretofore provided has been so mounted as always to tend to gouge the leather, 5. e. to dig into or cut into the leather beyond the extent desired. I have discovered that thistendency has been due to the relation of the work feeding mechanism and the knife, or rather, it

has been due to the position of the knife with relation to the direction of feed of the stock at the cutting point or edge where the stock meets the knife. My "invention therefore, resides mthe sides in the combination with a single-bevel knife of work feeding mechanism so related and relatively positioned that the body of the stock as it is fed against the edge of' said knife is maintained substantially flat sKIvIN-MACHINE.

Specification of Letters Patent. Patented Nov, 14, 1916, Application filed May 4, 1915. Serial N 0. 25,829. i

and the knife is set at an angle or in an obllque plane so as to wedge 0E. the skiving with ust the wedging action required for even cutting. For ordinary purposes, as in skiving rather heavy, stiff leather, I provide means to keep the body of the stock in en- PATNT onto,

gagement with one side,- preferably the bevel-side of theknife, while the other side, preferably the back-side or flat side of the knife (preferably close to the yielding feed invention relates to machlnes for roll or equivalent feeding'device), is at such an angle to the direction of body-movement of the stock at the cutting point'of the knife as to have a. wedging action on the stock where it is being on V .Stated less broadly, my invention, in its more restricted embodiment, requires that the single-bevel, knife shall be so set with relation to the direction of feed of the stock at the cutting point or edge of the knife that each face of the knife has a wedging action on the stock. The knife in the latter case is preferably so positioned that the skiving comes off at the back-side of the knife while the body of the stock passes on the bevelside of the knife. 1

In the accompanying drawings which I herewith present for more conveniently exhibiting my invention and explaining the principles thereof and the best mode in which I contemplate applying those principles, Figure 1 is a central, vertical, 'longitudinal section of a skiving machine containing a single-bevel knife so arranged and mounted with, relation to the work feeding mechanism as to embody my invention. Fig. 2 is a vertical, transverse, sectional view looking from the end of the machine toward the cutting edge of the knife, and Figs. 3 and 4 are views of the machine in side elevation and top plan partly broken away and sectioned.

It will be understood that in the drawing I-have endeavored merely to show a conventional skivingmachine, so far as concerns the general details, merely as a convenient means of-exhibiting and explaining my in-- vention, the latter, however, not being restricted in' any sense to this kind of a skiving machine, but having broad application to leather skiving, shaving and splitting machines in general. In a suitable frame 1 are mounted usual feed rolls 2, 3, the latter being shown as corrugated and yieldingly upscrew 6, both rolls being positively driven by sprocket chains 7, '8, engaging respectively sprocket wheels 9, 10 of the respective rolls, and sprocket wheels 11, 12 of shafts 13, 14 respectively, which are geared together byspur gears 15, 16 and provided with loose and fast pulleys 17 18 on theshaft 14. In general, all the mechanism thus far described may have infinite variety within the spirit and scope of my invention, it being essential merely that there shall be some kind of stock feeding mechanism to cause the stock to be approached or directed to the cutting edge of the knife at the right angle or direction or in the right relation as required by my invention.

As herein shown, immediately behind the feed roll 3 is a heavy transverse ledge or knife supporting block 19, on which is adjustably'secured by any suitable means, as by clamping bolts or screws 20, the singlebevel cutting knife 21, whose use it is the object of my invention to make possible.

Referring ,more particularly to Fig. 1, where my invention may most readily be apprehended, it will be seen that I have so mounted the knife 21 thatits beveled side 22 is uppermost, facing the smooth roll or gage roll 2, while the flat side or back 23 of the knife extends obliquely rearward and downward adjacent the yielding feed roll 3. In this position the body of the stock passes between the bevel '22 and the gage roll 2 while the skiving is diverted downward by the back' 23 of the knife and the corrugated roll 3.. I prefer to have the bevel edge or side 22 of the knife arranged thus to receive the wear due to the friction of the leather pieces being fed along because this facilitates the proper sharpening of the knife, promotes economy and tends to maintain a straight edge. All the sharpening of a single-bevel knife is done on the bevel side.

and if the knife were reversed from the position shown in the drawings so as to have the cutting on the flat side or back side 'instead of on the bevel side, the friction of the leather, asthe successive pieces of stock were fed along, would ultimately wear the back side hollow, so that a straight edge could no longer be secured by sharpening the bevel side. In other words, by so mounting the knife-that the cutting is done on the bevel side and the body of the stock is there: fore in engagement with the side where all the sharpening is done, thereby leaving the flat back side always flat or plane, the result is that a true, straight cutting edge is always readily maintained and the sharpening of the knife rendered easy and simple by being confined to the bevel edge while the opposite back side of the knife is left un touched by the sharpening tool and unworn by the stock. As shown, the feeding mechanism of the machine tends to feed the stock straight ahead in a horizontal plane. The knife is placed so that its cutting edge is back from the bight of the rolls only as far as is absolutely necessary in order to permit the latter to get a feeding grip on the stock. This detail is not peculiar to my invention as it has always been considered necessary to provide feeding grip just enough to afford the power necessary for aforward feeding of the stock to the knife and then have the knife mounted in position to begin cutting the stock as soon as possible as the stock moves rearward. The nearer the cutting edge of the knife is to the bight of the rolls the surer is-the skiving operation. This has always been theoretically the 'case, but

with a thicker, double-beveled knife the edge side of the knife and the skiving to pass on the other side of the knife, i. e. there must be proper clearance to permit the body of 'the stock to pass between the side 22 and the roll 2 and to permit the skiving to pass between the. back 23 and the roll 3. The most important feature of my discovery or invention when applied tov a two-roll feed resides in setting'the knife obliquely or on an incline with relation to the direction of the feed of the stock at the cutting point. By this means I use one edge orside as heretofore for the cutting and the other edge or side to do the prying off or to accomplish the wedging action of the knife on the stock. For the best results the knife is so set that both sides have a wedging function, i. e. the side next to the body of the stock tends to bend or wedge the body of the stock some what and the side away from the body tends to bend or wedge the skiving or split off portion of the stock. As, therefore, the bevel of the side 22 varies with different knives, the angle or inclination of the knife 'propefwill correspondingly vary for accomplishing the theoretically best results. For the bevel of knife shown in the drawing this angle is about 27 with relation to the direction of feed of the stock at the point where it meets the cutting edge. In a less degree the advantages of my invention are secured, however, by so arranging the knife with relation to the direction of feed of the stock that the side of the knife which engages and deflects the skiving-is oblique to the direction of feed at the cutting edge so as to have a wedging action on the skiving at the cutting edge, 2'. 6. so as to tend topry side. For securing the most complete re .sults' and best embodiment of my invention,

the proper and best angle of the knife, therefore, with relation to the directlon of feed of the stockat the cutting point, is deter- 7 mined by the direction of feed, a. 6., the location of the knife with reference to the bight of the rolls (or direction of feed impulse,

1 Whatever may be the feeding mechanism),

' i jend of the knife were dropped so as to tip the bevel 'of the face 22 of the knife, and the tangency of the edge of the knife with relation to the adjacent member or portion of the feedin mechanism. In explanation of the latter eature, and still viewing Fig. 1,

Imean that the angle of the knife must be such that the side of the knife which is adjacent the roll 3 tends, at each succeeding point rearward from the edge .of the knife to leave the roll, or in other words, there is no point in said side which is closer to the roll than is the cutting edge. This permits the skiving 'to ,be wedged away by the knife under the cooperating pull of the roll with entire'freedom and without any tendency to bind or choke between the knife and the roll. For instance, if, in Fig. 1, the rear the knife at such an angle that the back Of the lmifewere' closer to the roll 3 than the edge of the' knife, there would result a crowding or squeezing of the skiving between. the back of the knife and the'roll 3.

This would be improper. Referring now to the angle of the face'22 with relation to the direction of feed of the stock, it will be -40' knife, a divergence of the side 22 from the seen thatjthere must always be, as just explained, with reference to the back of the roll 2 at everypoint in said side back from the cutting edge, as distinguished from a convergence. The'knife, therefore, mustbe mounted within the range of these two extremes,'i. (2., so as to avoid on the one hand a convergence of the upper side (as herein shown, the side 22) with relation to the roll 2, and on the other hand, a convergence of.

' stand great pressure so as not to spring at the edge toward the yielding feed roll. By my invention the knife may be much thinner as the knife is set at such an angle that it diverts the strains which have heretofore tended to spring the edge so that they tend to counteract each other.

To sum up some of the principal advanand material, resulting-from the use of a single-bevel knife. The third is the simplification of the work of keeping such a machine in order, as it requires much less skill, according to my invention, than with the old'double-bevel knives. Not only is the original knife itself much" less expensive, but it is a comparatively simple matter to maintain a proper straight edgebe'causeall the sharpening comes on the single bevel, the maintenance of'an unvarying bevel is no longer so important as in the old doublebevel knives, the cutting edge may properly and readily be maintained thinner than heretofore and hence the knife adjusted closer in between the rolls, and the knife may be more easily and conveniently adjusted for stocks of different degrees of hardness and softness, etc.

I regard myself as the first tohave succeeded in making it possibleto use asinglebevel knife in a leather skiving machine, and also the first to employ such a knife so mounted that its back side operates to wedge away the skiving from the body of the leather piece being skived, and'hence considered both separately and together the invention is a pioneer and this is therefore entitled to be a foundation patent as to thesebroad features The generic claims to my invention are contained herein, and 'my aforesaid copending application, so far as it relates to this invention, is subordinate hereto. As implied in the foregoing statev ments of this paragraph, and as already stated in the earlier part of this specification,my invention is capable of a wide range of physical embodiments, and therefore, excepting as otherwise restricted, in certain of the claims, I am not limited to the particular mechanical construction,- arrangement and relation of parts shown in the drawings. I have used the word skiving to include the cutting off of one side or portion of a leather piece in or parallel to the general plane of the piece, and therefore to include evening, shaving, splitting, as distinguished from the transverse cutting or beveling of a leather. piece, in making belts for instance, where the opposite ends are beveled or cut through diagonally, in order to make a proper splice. The latter operation is not skiving in the proper sense as none of the problems and difiiculties which are solved by my invention are there presented, and hence almost any kind of a knife can be used. In explaining and defining my invention, I have'referred to the direction of feed of the stock at the cutting point and have referred to the feeding mechanism,

meaning thereby to characterize broadly these features and relations without limitation to any particular mechanism or relation. In the machine .of the drawings, the feeding mechanism is of the common type of feed roll machines in which the stock is nipped between the rolls and pushed by said nipping engagement toward and onto the knife. This, however, is only illustrative, being one of many kinds of feeding mechanism. If the feeding mechanism were of such a kind that it should vary the direction of approach of the stock to the edge of the knife at said edge, the critical direction to be considered inconnection with my invention would be the direction which the stock in fact might have at the cutting point or edge of the knife and not the direction of movement which the stock might have at any other point either beyond or back of said cutting edge.

My invention is accordingly further described and defined in the form of claims, as follows:

1. In a machine of the kind described, the combination with stock feeding mechanism constructed and arranged to maintain the stock substantially flat and plane, of a 'single-bevelknife having its bevel-side mounted to engage with the body of the stock being skived, and so set with relation to the direction of feed of the stock at the cutting edge of the knife that the back side of the knife has a wedging action on the stock, said feeding mechanism including unyielding means for holding the side of the stock adjacent thereto at a fixed distance from said bevel-side of the knife.

2. In a machine of the kind described, the combination with stock feeding means constructed and arranged to maintain the stock substantially flat and plane, of a singlebevel knife so set with relation to the direction of the feed of the stock' at the cutting point that each face of the knife has a wedging action on the stock, said feeding mechanism including means located on that 4 side of the knife which receives the body of the stock, constructed and arranged to co- .said roll and its adjacent side extending thence rearwardly and divergently from said roll and yet obliquely to the direction of feed of the stock at the cutting edge of said knife, said feeding mechanism including means opposite said yielding roll and knife edge constructed and arranged to cooperate with said knife, so set, and with said roll to maintain the side of the body of the stock adjacent said means at a fixed distance fromthe cutting edge of the knife.

4. In a machine of the kind described, feed rolls for receiving between them successive pieces of stock and positively feeding said stock to be skived, and a singlebevel skiving knife mounted rigidly behind said rolls with its cutting edge extending between the rolls close to the bight thereof and having its opposite sides adjacent said edge mutually divergent from the respective adjacent rolls at all points back of the cutting edge, one of said rolls being yielding and close to the adjacent side of the knife and the other roll being unyielding and at a greater distance from the adjacent side of the knife to permit the passage of the body of the stock, said latter roll being so positioned with relation to the other roll and to the knife, mounted as stated, as to maintain the side of the body of the stock contacting therewith at a fixed distance from the cutting edge of the knife throughout the skiving or splitting operation.

In testimony whereof, I have signed my name to this specification, in the presence of two subscribing Witnesses.

ELMER P. NICHOLS.

Witnesses:

JAMES R. HODDER, SEBASTIAN. VAUGHAN. 

